If a plurality of elevators are installed together, group control is normally performed in order to efficiently operate these elevators. If group control is applied to a one-shaft multi-car system elevator in which a plurality of cars operate in one shaft, the elevator system must be controlled so that transportation efficiency is improved while avoiding the collision between the cars operating in the same shaft. This is the greatest difference from a normal elevator system in which one car operates in one shaft.
Proposed conventional techniques taking this into account include a multi-car system elevator system which performs cyclic operations capable of horizontal movement and in which a car entry prohibited section is set to perform control such that the car does not enter this section (see for example, Patent Document 1).
Another proposed conventional technique is a system which sets exclusive zones in which the respective cars are exclusively operated and a common zone and which provides means for retracting the car from the common zone to the exclusive zone and means for determining whether or not it is possible to advance from the exclusive zone into the common zone (see for example, Patent Document 2).    Patent Document 1: Japanese Patent No. 3029168    Patent Document 2: Japanese Patent Laid-Open No. 2003-160283